https://github.com/sea-boat/mysql-protocol
mysql连接如果想要改变该连接默认的schema，则客户端可以向服务端发送初始化DB命令包。
| 类型 | 名字 | 描述 |
|---|---|---|
| int<3> | payload长度 | 按照the least significant byte first存储，3个字节的payload和1个字节的序列号组合成报文头 |
| int<1> | 序列号 | |
| string | payload | 报文体，长度即为前面指定的payload长度 |
Payload
1 [02] COM_INIT_DBstring[EOF] schema name
更多详情 ： http://dev.mysql.com/doc/internals/en/com-init-db.html
初始化命令包
/**
*
* @author seaboat
* @date 2016-09-25
* @version 1.0
* <pre><b>email: </b>849586227@qq.com</pre>
* <pre><b>blog: </b>http://www.gxlcms.com/;/pre>
* <p>mysql init db packet.</p>
*/public class InitDBPacket extends MySQLPacket {
public byte[] schema; public void read(byte[] data) {
MySQLMessage mm = new MySQLMessage(data);
packetLength = mm.readUB3();
packetId = mm.read();
mm.read(); // skip COM_INIT_DB
this.schema = mm.readBytes();
} public void write(ByteBuffer buffer) {
BufferUtil.writeUB3(buffer, calcPacketSize());
buffer.put(packetId);
buffer.put(COM_INIT_DB);
buffer.put(schema);
} @Override
public int calcPacketSize() { int i = 1;
i += schema.length; return i;
} @Override
protected String getPacketInfo() { return "MySQL Init DB Packet";
}
}下载本文